So the service engine light came on today and I took it by AutoZone and had them run the code. It is P0410 which is "The PCH has determined that a malfunction exists in the secondary air injection system" Any idea what this is or where to start on troubleshooting?

 

GEE it would sure be nice to have some CRITICAL VEHICLE INFORMATION, but you need to check for a blown 30 amp maxi fuse right beside the battery behind the right headlight in the right fender. This code is usually caused by a blown fuse which is caused by water intrusion into the secondary AIR injection pump. There is an updated kit to relocate the inlet hose for the pump to keep water from getting in it.

 

Yea I guess some specs would help. Sorry. 2001 Blazer 4wd 4.3L Auto. Thanks for the tip. I will go check now.

 

Not the fuse. Just checked and it is good.

 

Any more ideas?

 

It is possible that the air pump is locked up or just gone bad. It is located under the radiator. If you remove it, you may be able to bench test it to ensure that it is working.